The human rights violations in Sudan are fairly intense.  The following is an excerpt from the State Department's report on Sudan (website featured below):

In Darfur government forces, janjaweed, and Darfur rebel groups committed serious abuses during the year, including the reported killing of at least several thousand civilians. Government and janjaweed militias razed numerous villages of African tribes, and committed acts of torture and violence against women. Darfur rebel groups were also responsible for rape and attacks on humanitarian convoys and compounds in order to steal equipment and supplies, resulting in death and injury to humanitarian workers. According to the UN, more than 200,000 persons have died, two million civilians have been internally displaced, and an estimated 234,000 refugees have fled to neighboring Chad since the conflict began in 2003. Despite the presence in Darfur of the African Union-led international monitoring force (African Union Mission in Sudan or AMIS), security remained a major problem and deteriorated during the year, with reports of violence increasing during the latter half of the year.

The websites below also give some additional references where further research can be undertaken.  I would also probe the connection to Sudanese connection to China, another area of the world where human rights questions abound.